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path: root/drivers/dma/xilinx
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Diffstat (limited to 'drivers/dma/xilinx')
-rw-r--r--drivers/dma/xilinx/xilinx_dma.c39
1 files changed, 31 insertions, 8 deletions
diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 02880963092f..fd9f37bafab0 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -425,6 +425,7 @@ struct xilinx_dma_config {
* @rxs_clk: DMA s2mm stream clock
* @nr_channels: Number of channels DMA device supports
* @chan_id: DMA channel identifier
+ * @max_buffer_len: Max buffer length
*/
struct xilinx_dma_device {
void __iomem *regs;
@@ -444,6 +445,7 @@ struct xilinx_dma_device {
struct clk *rxs_clk;
u32 nr_channels;
u32 chan_id;
+ u32 max_buffer_len;
};
/* Macros */
@@ -960,6 +962,25 @@ static int xilinx_dma_alloc_chan_resources(struct dma_chan *dchan)
}
/**
+ * xilinx_dma_calc_copysize - Calculate the amount of data to copy
+ * @chan: Driver specific DMA channel
+ * @size: Total data that needs to be copied
+ * @done: Amount of data that has been already copied
+ *
+ * Return: Amount of data that has to be copied
+ */
+static int xilinx_dma_calc_copysize(struct xilinx_dma_chan *chan,
+ int size, int done)
+{
+ size_t copy;
+
+ copy = min_t(size_t, size - done,
+ chan->xdev->max_buffer_len);
+
+ return copy;
+}
+
+/**
* xilinx_dma_tx_status - Get DMA transaction status
* @dchan: DMA channel
* @cookie: Transaction identifier
@@ -992,7 +1013,7 @@ static enum dma_status xilinx_dma_tx_status(struct dma_chan *dchan,
list_for_each_entry(segment, &desc->segments, node) {
hw = &segment->hw;
residue += (hw->control - hw->status) &
- XILINX_DMA_MAX_TRANS_LEN;
+ chan->xdev->max_buffer_len;
}
}
spin_unlock_irqrestore(&chan->lock, flags);
@@ -1254,7 +1275,7 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
/* Start the transfer */
dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
- hw->control & XILINX_DMA_MAX_TRANS_LEN);
+ hw->control & chan->xdev->max_buffer_len);
}
list_splice_tail_init(&chan->pending_list, &chan->active_list);
@@ -1357,7 +1378,7 @@ static void xilinx_dma_start_transfer(struct xilinx_dma_chan *chan)
/* Start the transfer */
dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
- hw->control & XILINX_DMA_MAX_TRANS_LEN);
+ hw->control & chan->xdev->max_buffer_len);
}
list_splice_tail_init(&chan->pending_list, &chan->active_list);
@@ -1718,7 +1739,7 @@ xilinx_cdma_prep_memcpy(struct dma_chan *dchan, dma_addr_t dma_dst,
struct xilinx_cdma_tx_segment *segment;
struct xilinx_cdma_desc_hw *hw;
- if (!len || len > XILINX_DMA_MAX_TRANS_LEN)
+ if (!len || len > chan->xdev->max_buffer_len)
return NULL;
desc = xilinx_dma_alloc_tx_descriptor(chan);
@@ -1808,8 +1829,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_slave_sg(
* Calculate the maximum number of bytes to transfer,
* making sure it is less than the hw limit
*/
- copy = min_t(size_t, sg_dma_len(sg) - sg_used,
- XILINX_DMA_MAX_TRANS_LEN);
+ copy = xilinx_dma_calc_copysize(chan, sg_dma_len(sg),
+ sg_used);
hw = &segment->hw;
/* Fill in the descriptor */
@@ -1913,8 +1934,8 @@ static struct dma_async_tx_descriptor *xilinx_dma_prep_dma_cyclic(
* Calculate the maximum number of bytes to transfer,
* making sure it is less than the hw limit
*/
- copy = min_t(size_t, period_len - sg_used,
- XILINX_DMA_MAX_TRANS_LEN);
+ copy = xilinx_dma_calc_copysize(chan, period_len,
+ sg_used);
hw = &segment->hw;
xilinx_axidma_buf(chan, hw, buf_addr, sg_used,
period_len * i);
@@ -2628,6 +2649,8 @@ static int xilinx_dma_probe(struct platform_device *pdev)
/* Retrieve the DMA engine properties from the device tree */
xdev->has_sg = of_property_read_bool(node, "xlnx,include-sg");
+ xdev->max_buffer_len = XILINX_DMA_MAX_TRANS_LEN;
+
if (xdev->dma_config->dmatype == XDMA_TYPE_AXIDMA)
xdev->mcdma = of_property_read_bool(node, "xlnx,mcdma");